Controlling means for fuel injection engines



Feb. 18, 1936. E. DODSON CONTROLLING MEANS FOR FUEL INJECTION ENGINES Filed may 28, 1935 0 o i- -Q a as E RN I Q m s i. h 3 L m o a w o a A W V 0 o .R o Q m mm \h a 0 Km 1 r L I Ix N N 0 Q 1 .v Q

Feb. 18, 1936. E. DODSON 2,031,527

CONTROLLING MEANS FOR FUEL INJECTION ENGINES Filed May 28, 1935 3 Sheets-Sheet 2 Feb. 18, 1936. E. DODSON 2,031,527

CONTROLLING MEANS FOR FUEL INJECTION ENGINES Filed May 28, [1935 3 Sheets-Sheet 5 Patented F eb. 18, 1936 UNITED- ST T S CONTROLLING MEANS FOR FUEL INJECTION ENGINES Edward Dodson, Streatham, London, England Application May 28, 1935, Serial No. 23,911 In Great Britain April 23,1935

70laims.

This invention relates to means for controlling fuel injection engines-i. e. engines which are fed with their fuel from a measuring pump or other injecting device (hereinafter referred to as a pump) as distinct from those engines which have their fuel supplied by means of a carburetterand while the invention is not confined to aircraft engines certain aspects of the invention are more particularly applicable to that type of engine than to engines which will operate under more or less constant barometric conditions.

It is known to use a fuel injection scheme on aircraft engines, but in the known arrangement it is impossible to proportion the fuel to the varying conditions of load and altitude automatically without the necessity for any skilled operation by the pilot.

In fuel injection. engines, the fuel injection pump is usually driven by the engine so that the injection is timed in accordance with engine speed, but it is also necessary to vary the amount of fuel in accordance with induction pipe prwsure. The quantity of fuel supplied is not, however, required to be proportional to the induction pipe pressure at varying loads because the fuel is, for instance, required to be supplied in greater proportions when the air throttle is closed to its engine idling position, and is again required to be supplied in greater proportions when the air throttle is at the normal full throttle position than when the throttle is partly closed to the cruising position. This effect of increasing the proportion of fuel in accordance with the throttle position is usually obtained by a power jet I and is known as the power jet efiect.

To obtain the utmost economy for cruising, it is advisable to reduce the proportion of fuel to air well below that which will provide the weakest mixture necessary for maintaining power, and at the same time the ignition should be advanced. Under these conditions the engine will stand relatively large loads on ultra weak mixtures without overheating.

For purposes of providing extra power for take off from the ground and other emergencies, it is desirable to alter the character of the fuel when power entailing higher than normal induction or supercharging pressures are used; the

alteration being either that ofv excessive enrichment of the fuel, or a change in the character of the fuel, so as to enhance its anti-detonating properties or both.

In very high compression ratio engines, or supercharged engines, it is necessary to use a device known as a boost control that will automati- I cally restrict the supercharging pressures to that which is safe for the engine. It is also desirable that means should be available for increasing the normal super-charging pressure, as permitted by the boost control, to a higher pressure for take 5 oil, or for an emergency, but the increased pressure should be provided only when an anti-detonating mixture is also supplied.

A supercharged engine in an aircraft climbing at constant supercharged pressure as it ap- 10 preaches the rated height of such engine, will develop a higher brake mean effective pressure than it did at sea level, with a consequential increase in speed and internal heat. This feature is due, to a large extent, to better exhaust scav- 15 enge, arising from the lower external air pressures. It is consequently desirable that the mixture should be enriched, or its quality altered, as the rated height of the engine is approached,

so as to enhance its anti-detonation properties. 20

It is, moreover, essential to prevent weak mixtures being obtained under high power conditions, and when ultra weak mixtures are used it is advisable to advance the ignition timing.

The object of this invention is primarily to 25 provide wholly automatic controlling means to ensure that the quantity of fuel supplied to the engine is varied as is requisite for variations in load, engine speed, and/or altitude, and also to prevent excessive pressure of air being supplied 30 to the engine in order to avoid destructive pressures being obtained at or near sea level on a super-chargedor other high compression ratio engine. A further object is to enable all the requirements enumerated above to be automati- 35 cally obtained sothat even an unskilled pilot would not be liable to damage the engine.

According to this invention the means for controlling the pump of fuel injection engines in accordance with induction pipe pressures, comprises 40 provides the necessary power for actuating said 50 controlling member. The device for varying the controlling effect may be arranged to increase the fuel ratio when the throttle lever is in its engine idling position and/or when the said throttle lever approaches its normal full throttle position, both 55 relative to the intermediate cruising positions of the throttle control.

Another feature of this invention is to provide a device to further increase the fuel-air ratio and/or to alter the character of the fuel so as to increase its antidetonating properties when the throttle control is moved beyond its normal full throttle position. In a supercharged engine controlled by a .boost control" this device for further increasing the fuel-air ratio is also combined with a device for overriding the boost control so as to cause this control to open the throttle more widely and thus permit of greater power being developed.

A further feature of this invention is to provide a device operated by the mixture control lever, to override the boost control, to give extra power for take off, and at the same time enrich the mixture or alter and improve its antidetonating qualities, which is preferably arranged to take place when the mixture control is placed in its most rearward position in the quadrant.

A still further feature of this invention .is to provide another pressure sensitive device exposed to atmospheric pressure and operatively connected to the induction pressure sensitive device so as to act on the latter in such a way as to compensate for the effect of atmospheric pressure differences due to change in altitude.

In controlling fuel injection devices ofsupercharged engines according to this invention it is important to use a variable datum boost control as described in the applicant's United States Patent No. 1,995,800, because this instrument renders it impossible to obtain the normal boost until the throttle control is in full throttle position and, moreover, each position of the throttle control gives a definite supercharg ng pressure below the rated height of the engine. The use of this variable datum boost control renders it feasible and certain to control the ignition timing by connecting the ignition advance and retard device with the throttle control and also by the device for varying the effect of the injection pump controlling member for varying the fuel-air ratio to give the aforesaid power jet effect, and for slow running. Thus the power jet effect will only be obtained when the controlling effect of the devices is such that the supercharging pressure approaches the normal full pressure below the rated height in spite of the fact that the opening of the air throttle will be increased with increase in altitude by the boost control. It might be explained that the reason this only applies below the rated height is that because above that height both the throttle control and the air throttle will be in the fully open position at the same time.

The induction pressure sensitive device is pref erably in the form of an aneroid comprised of several separate capsules, a bellows or like deice enclosed within a container of such a form as to allow the aneroid to extend freely but limit its expansion so that should one of the capsules or the bellows or the like be punctured it will still be possible by moving a mixture control to cause suflicient fuel to be supplied to allow of at least cruising on a weak mixture automatically regulated in accordance with altitude.

A form of the controlling means according to this invention is shown by way of example in the accompanying drawings in which:-

Fig. 1 is a general arr'angementof the control devices, with parts in section to show the enclosed operating devices.

Fig. 2 is an elevation of the throttle control and mixture control separated from the other devices and drawn to an enlarged scale to show the means for causing one of these to interengage with the other.

Fig. 3 is a plan view of the casing for the throttle control and the mixture control.

Fig. 4 is an elevation of the means for operating the adjusting lever of the advance and retard device of the ignition from the throttle. control and the mixture control.

Fig. 5 is an elevation showing one of the aneroids constituting the pressure sensitive devices, and illustrating in section the container for limiting the extension of said aneroid if this should be punctured.

Fig. 6 is a perspective view of the container for the aneroid.

In the construction illustrated which shows a relay or servo-motor operated device responsive to induction pipe pressures which pressures are communicated from the pressure side of the supercharging blower through the conduit i to the casing 2 containing an aneroid capsule 3 (hereinafter referred to as the induction pressure capsule) to cause this capsule to operate a piston valve 4 controlling the flow of pressure fluid to the relay piston I, which in turn operates the injection pump controlling lever B, so that said pump will give a fuel charge to the engine proportional to the induction pipe pressures.

A sliding sleeve valve 6, surrounding the piston valve 5, is operated by lever 6" from a cam I on the mixture control 8 which has three positions, that indicated at A being the weak automatic position, that indicated at B the rich automatic position and that at C the take-off position, said sleeve valve in effect changes the range of control of the piston valve 5 so that, while still varying the fuel charge automatically in accordance with induction pipe pressures, the fuel pump gives a weaker or a richer range of fuel according to the setting of the mixture control at either the position A or 13 throughout the engine throttle range. Fixed to the mixture control lever 8 by means of an arm l and a link 8 is another cam III which, by operating a lever II, is adapted to push a second capsule l2 (hereinafter referred to as the atmospheric capsule) which is contained in a casing ll open to atmospheric pressure. This atmospheric capsule I2 acts through the rod ll, lever II and rod I! to shift the induction capsule I and thus cause a greater fuel charge to be given by the pump when the mixture lever is put into the take-off position marked C. The mixture control 8 is also connected by an arm H on a link H to an override cam l8 acting through the lever ll" on the cap I! of a boost control ll as described .in my United States Patent No. 1,995,800 so that the range of the boost control is varied by shift-- ing the position of its capsule as the mixture control is moved from its rich automatic position marked B to its take-off position marked 0 to allow extra supercharging pressure for take-oil, but still leave the boost control to act through the linkages 2|, 2| and 22 on the throttle valve 21 in the induction pipe 24 so as automatically to maintain the supercharging pressure constant with change of altitude.

The atmospheric pressure capsule I! will expand as height is gained up to a limit allowed by an adjustable container 2| enclosing said capsule. When the mixture control'is in the takeoff position the capsule will expand to said limit aosaoar g 3 as height is gained on climbing and thereby increase the fuel charge. The reason for this increase is that an engine climbing from'the ground at constant supercharging pressure will. increase its brake mean effective pressure as height is gained up to that height to which the supercharger can maintain ground level supercharg- 4 it is arranged to enrich the mixture either enough to prevent the higher brake mean effective pres-' sures from being obtained or to prevent overheating or detonation if they are obtained.

In some cases it is desirable to add to or sub-' stitute for the before-mentioned mixture enrichment obtained with the ordinary fuel,.another fuel of higher anti-detonating qualities, such as alcohol or alcohol and water. A plungervalve 26 operably connected to the mixture control, through the link 9, cam Ill and the rocker 21 on said cam so as to be opened when the mixture control is placed in its take-oil position marked C, is a convenient means of adding this extra fuel. This fuel is induced to flow from a supply tank (not shown) through the pipe 28 which is not connected to the injection pump but is connected into the eye of the supercharging blower.

On the cover of the boost control l9, in addition to the aforesaid override cam l8, there is another cam 29 operably connected by the link 38 to the throttle control 3|. This cam 29 is the variable datum cam. Its purpose is, as explained in the United States Patent No. 1,995,800 referred to above, to ensure that the usual supercharging pressure cannot be'obtained with a weak mixture. The throttle control 3| and the mixture control 8 are contained in the casing 82 adapted to be mounted in the cockpit of the aeroplane, said casing being provided with two slots 88 and 84 in which said controlswork. These controls are arranged as described in my prior United States Patent No. 1,998,362 so that the mixture control is connected to an actuating lever 35 pivoted at 86 on the casing and provided with an upward ex-' tension 31, while the throttle control is provided with two projections 38 and 99. These projections cooperate with the lever 35 to cause the throttle control to control the position of the mixture control. The throttle control 8| has no defined position except at the ends of the slot in the casing in which it works, but is adapted to be adjusted to any position from the slow run-' ning position marked I through the cruising position marked 11 to the full throttle position marked III. It is also possible by moving it into an extension of the slot, breaking a seal 84" (Fig. 3) to move the throttle control to an emergency position marked IV. When the throttle control is moved from the cruising position marked II to the slow running position marked I, if the mixture control 8 is at the weak automatic position A, then the projection 39 will engage with the lever 85 and cause this to move the mixture'control to its rich automatic position B. On the other hand, if the throttle control is moved in the other direction into the full throtle posiion III, while the mixture control is at the weak automatic position A, then the projection 88 will engage the lever 88 and cause this to move the mixture control 8 to its rich automatic position B, and, if the throttle. control is further moved into its emergency position IV. the projection 88 and lever 88 will further move the mixture control into its take-oil! position C, in which it gives an ultrarich mixture as hereinbeiore explained.

"The throttle control 8| and the mixturecontrol 8 are also connected to an adjusting arm 40 advance and retard mechanism indicated at 4| of the magneto 4| or other ignition device. This adjusting arm 48 is adapted to be operated by the mechanism shown in Fig. 4 and comprises operably connected by the link 4| to the known a cam slotted sector 42 on the throttle control 3! having its follower 48 mounted on one end of a floating lever 44 pivoted intermediate its ends and connected at its other end 45 by a link to the adjusting arm 48. The fulcrum oi the floating lever 44 is carried at the end of one arm of a hell I crank lever 46, the other arm of which is connected by a link 41 to the mixture control 8. The arrangement is such that adjustments of the throttle control rock said floating lever about its fulcrum on the end of the bell crank lever asa centre, while adjustments. of the mixture control rock the floating lever about the axis of the follower 43 as a centre.

The throttle control 3| is further connected by the link 49 to the cam 50 provided with two "rises 5|, 52 with an intermediate dwell 53. The

tainer as shown in Figs. 5 and 6. The container consists of two cup-shaped parts 55, 56 the base of one part being fixed to one end of the capsule and the base of the other part to the other end of the capsule. The sides of said parts, which extend around the sides of the capsule, are gapped at three points 51 to form three tongues 58 and the parts are so arranged that the tongues on one part project into the gaps on the other part.

The ends of the tongues are formed with outstanding flanges 59 against which is fixed a ring 60. A spring BI is arranged between the two rings 60 so that by compressing this spring the container can expand with the capsule until the spring is fully compressed. If, therefore, one of the capsules is, punctured, this will only expand the container until the spring is fully compressed.

The container and spring thus impose a limit on the amount of expansion of the capsule.

What I claim as my invention and desire to secure by Letters Patent is 1-. Means for controlling fuel injection engines comprising a fuel controlling device for varying the amount of fuel supplied to said engines, an I induction pressure sensitive device, means operatively connecting said induction pressure sensitive device wlth said controlling device, a throttle control, throttle control actuated means for operating said controlling, device independently of said induction pressure sensitive device, and means for operating said controlling device independently of said throttle controlactuated means and said induction pressure sensitive device when the throttle control is moved'beyond its normal full throttle position into an emergency position.

2. Means for controlling supercharged fuel in- Jection-engines comprising a fuel controlling device for varying the amount of fuel supplied to said engines, an induction pressure sensitive device, means operatively connecting said induction pressure sensitive device with said controlling device, a throttle control, throttle control actuated means operating said controlling device independently of said induction pressure sensitive device, means for operating said controlling device independently of said throttle actuated means and said induction pressure sensitive device when the throttle control is moved beyond its normal full throttle position into an emergency position, a boost control adapted to restrict the supercharging pressure to a predetermined pressure, means for overriding said boost control, and means operably connecting said overriding means to said throttle control so that the boost control is overriden when said throttle control is moved into said emergency position.

3. Means for controlling supercharged fuel injection engines comprising a fuel controlling device for varying the amount of fuel supplied to said engines, an induction pressure sensitive device, means operatively connecting said induction pressure sensitive device with said controlling device, a throttle control, throttle control actuated means operating said controlling device independently of said induction pressure sensitive device, means for operating said controlling device independently of said throttle actuated means and said induction pressure sensitive device when the throttle control is moved beyond its normal full throttle position into an emergency position, a boost control adapted to restrict the supercharging pressure to a predetermined pressure, means for overriding said boost control, means operably connecting said overriding means to said throttle control so that the boost control is overridenwhen said throttle control is moved into said emergency position, and an atmospheric pressure sensitive device operatively connected to said induction pressure sensitive device so as to act to compensate for the effect of atmospheric pressure diflerences.

' 4'. Means for controlling supercharged fuel inlection engines comprising a fuel controlling device for varying the amount of fuel supplied to said engines, an induction pressure sensitive device, means operatively connecting said induction pressure sensitive device with said controlling device, a throttle control, throttle control actuated means operating said controlling device independently of said induction pressure sensitive device, means for operating said controlling device independently of said throttle actuated means and said induction pressure'sensitive device when the. throttle control is moved beyond its normal full throttle position into an emergency podtion, a boost control adapted to restrict the supercharging pressure to a predtermined pressure, means for overriding said boost control, means operably connecting said overriding means to said throttle control so that the boost control is overridden when said throttle control is moved into said emergency position, and means operable by the throttle control for changing the datum of said boost control.

5. Means for controlling fuel injection engines comprising a fuel controlling device for varying the amount of fuel supplied to said engines, an induction pressure sensitive device, means operatively connecting said induction pressure sensitive device with said controlling device, a throttle control, throttle control actuated means for operating said controlling device independently of said induction pressure sensitive device, a mixture control, and a mixture control actuated means for operating said controlling device independently of said induction pressure sensitive device adapted to vary the range of fuel charge according to the setting of the mixture I sure differences.

7. Means for controlling supercharged fuel in- Jection engines comprising a fuel controlling device for varying the amount of fuel supplied to said engines, an induction pressure sensitive device, means operatively connecting said induction pressure sensitive device with said controlling device, a throttle control, throttle control actuated means operating said controlling device inde-- pendently of said induction pressure sensitive device, means for operating said controlling device independently of said throttle actuated means and said induction pressure sensitive device when the throttle control is moved beyond its normal full throttle position into an emergency position, a boost control adapted to restrict the supercharging pressure to a predetermined pressure, means for overriding said boost control.means operably connecting said overriding means to said throttle control so that the boost control is overridden when said throttle control is moved into said emergency position, valve controlled means for supplying an anti-detonating fuel to the engine, and means for opening the valve on said valve controlled means when the throttle lever is moved into its emergency position.

EDWARD DODSON. 

